This invention relates to a recording medium in which a plurality of packets recorded in a program area are aggregated and which has a management area for batched management of the aggregated packets, a reproducing device for reproducing data from the recording medium, a recording device for recording data to the recording medium, a reproducing method, and a recording method.
Recently, there is known a recording device for recording image signals and audio signals of a dynamic image or a still image shot by a user to a recording medium such as an optical disc or a magnetic tape. In the conventional recording device, in the case where the user shoots images, the recording position of shots that are individually shot is managed in a management area.
In this case, with an ordinary optical disc, the recording position is managed in a management area referred to as TOC (table of contents), but it has a problem that the number of manageable shots is finite. Specifically, if shot each consisting of 100 Kbytes are recorded onto a recording medium having a capacity 640 Mbytes, approximately 6400 shots can be recorded. However, if the number of shots that can be actually managed in the management area is limited to 1000, recording cannot be carried out further even though a recordable area of approximately 540 Mbytes is left on the optical disc. Thus, there arises a problem that the recording area cannot be effectively utilized.
FIGS. 1A and 1B show a disc image of a conventional optical disc and a table showing the management form of its management area TOC, respectively. In the case where three shots are recorded as shown in FIG. 1A, the recording start position (start address) and the recording end position (end address) of each shot are managed in the from of table as shown in FIG. 1B, in the TOC as the management area. However, if the number of shots managed in the table is finite, there is an inconvenience that recording cannot be carried out further even though the recording capacity is left in a program area, which is a recordable area.
In view of the foregoing problem, it is an object of the present invention to provide a recording medium in which main data to be recorded in a program area is packetized into packets each having a header (packet header) for managing the data length of the individual packet, and in which a management area (packet index) for batched management of a pack in aggregating and managing a plurality of packets as a pack is provided so that the individual packets included in the entire pack (that is, aggregated packets) can be accessed by reproducing the header (packet property) included in each pack at the time of access and reproducing the management area (packet index) on the inner circle in advance, and a reproducing device for reproducing data from the recording medium.
It is another object of the present invention to provide a recording device in which the operation is switched between management of an aggregated plurality of packets and management of each of individual packets in accordance with the quality of contents, which is a recording target.
A recording medium according to the present invention comprises: a program area in which a plurality of aggregated unit packets are discretely recorded as a pack, each packet consisting of a header section having data length of the entire packet managed therein and a main data section; a first management area for managing the recording address of the packets in the program area; and a second recording area in which the total number of packets included in the pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets are managed.
A reproducing device according to the present invention is adapted for reproducing data from a recording medium including a program area in which a plurality of aggregated unit packets are discretely recorded as a pack, each packet consisting of a header section having data length of the entire packet managed therein and a main data section, a first management area for managing the recording address of the packets in the program area, and a second recording area in which the total number of packets included in the pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets are managed. The reproducing device comprises: reproducing leans for reproducing the first management area, the second management area and the program area; storage means for storing management information reproduced from the first management area and the second management area by the reproducing means; and control means for controlling transfer of the reproducing means on the basis of the management information stored in the storage means when access to an arbitrary pack of the plurality of aggregated packets is instructed.
A recording device according to the present invention is adapted for recording digital video signals to a recording medium including a program area in which a plurality of aggregated unit packets are discretely recorded, each packet consisting of a header section having management information recorded therein and a main data section, and a management area in which first management information consisting of the total number of packets included in a pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets or second management information consisting of the data length of each of the packets is selectively managed. The recording device comprises: blocking means for blocking inputted digital video signals by each predetermined length; discrimination means for discriminating the quality of the blocked digital video signals; first management information generation means for generating the first management information in the case where it is discriminated by the discrimination means that the digital video signals have low quality; and recording means for recording the first management information generated by the first management information generation means to the management area.
Also, a recording device according to the present invention is adapted for recording digital audio signals to a recording medium including a program area in which a plurality of aggregated unit packets are discretely recorded, each packet consisting of a header section having management information recorded therein and a main data section, and a management area in which first management information consisting of the total number of packets included in a pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets or second management information consisting of the data length of each of the packets is selectively managed. The recording device comprises: blocking means for blocking inputted digital audio signals by each predetermined length; memory means for storing the blocked digital audio signals; discrimination means for discriminating the quality of data stored in the memory means; first management information generation means for generating the first management information in the case where it is discriminated by the discrimination means that a predetermined quantity or more of the blocked digital audio signals are stored in the memory means; and recording means for recording the first management information generated by the first management information generation means to the management area.
A reproducing method according to the present invention is adapted for reproducing data from a recording medium including a program area in which a plurality of aggregated unit packets are discretely recorded as a pack, each packet consisting of a header section having data length of the entire packet managed therein and a main data section, a first management area for managing the recording address of the packets in the program area, and a second recording area in which the total number of packets included in the pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets are managed. The reproducing method comprises: a step of reproducing the first management area, the second management area and the program area; a step of storing management information reproduced from the first management area and the second management area to a memory; a step of discriminating the presence/absence of an instruction to access an arbitrary pack of the plurality of aggregated packets; and a step of accessing an arbitrary packet designated by the access instruction on the basis of the management information stored in the memory.
A recording method according to the present invention is adapted for recording digital video signals to a recording medium including a program area in which a plurality of aggregated unit packets are discretely recorded as a pack, each packet consisting of a header section having data length of the entire packet managed therein and a main data section, and a management area in which first management information for managing the total number of packets included in a pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets or second management information for managing the data length of each of the packets is selectively managed. The recording method comprises: a step of discriminating the quality of blocked digital video signals; a step of generating the first management information in the case where it is discriminated at the step of discriminating that the blocked digital video signals have low quality; and a step of recording the generated first management information to the management area.
Moreover, a recording method according to the present invention is adapted for recording digital audio signals to a recording medium including a program area in which a plurality of aggregated unit packets are discretely recorded as a pack, each packet consisting of a header section having data length of the entire packet managed therein and a main data section, and a management area in which first management information for managing the total number of packets included in a pack of the plurality of aggregated packets and the total length of data included in the pack of the plurality of aggregated packets or second management information for managing the data length of each of the packets is selectively managed. The recording method comprises: a step of blocking inputted digital audio signals; a step of storing the blocked digital audio signals to a memory; a step of discriminating whether the quantity of digital audio signals stored in the memory is equal to or greater than a predetermined quantity; a step of generating the first management information in the case where it is discriminated at the step of discriminating that the quantity of blocked digital audio signals stored in the memory is equal to or greater than a predetermined quantity; and a step of recording the generated first management information to the management area.